I'm looking to piece together a cheap, simple set-up for (primarily) outdoor portrait shoots. Basically, the main concern is being able to fill in some shadows when I am shooting. It'd also be nice to be able to shoot some basic night/dusk stuff, but it's not essential.

I'm looking to spend as little as possible at the moment. I'm thinking the following set-up could work for around $200. Please let me know your thoughts. I shoot a 50D, FWIW.

That puts me at <$250 shipped. Worth going for? Some shots from my recent shoot seriously needed some fill light, so it's time to make a move. A 70-200/2.8 is most important on my agenda, so spending serious money on a little lighting rig isn't possible right now.

Technically, fill light doesn't need to be off-camera. It's purpose is to give a base amount of light to the scene/subject and it can do that from the same angle as the camera.

Your main/key light should be off-camera, because that is the light that casts shadows and gives your subject some depth.

Of course, when you have an off-camera light you can use it as a main light as well, using the ambient light for fill.

Also, one of the best things for outdoor fill light is a reflector. With a reflector you don't have to worry about figuring the flash power and you don't have to limit your shutter speed to the max sync speed.

You are trying to attract customers and you want to skimp on lighting equipment?

I can appreciate your enthusiasm but, don't agree with this line of thinking for building a business.

What if you're doing your "free portrait sessions" and one of these items becomes unreliable or breaks on you? People will be cranky, and it's a free session. Imagine what they'd think if they were paying you.

Skimping on lighting because you need the $ for a good lens means that you're rushing into this venture not fully prepared.

My main concern is the light-duty light stand you are considering--it's simply too lightweight,and designed for indoor use. You need to have a light stand that can handle uneven ground, so a C-style light stand with a sliding leg like this one is close to the absolute ideal basic stand for location work

This type of C-style stand (also sometimes referred to as a turtle base stand) is also a lot heavier than an inexpensive aluminum studio stand,and will need MUCH less sandbag weight (if any) to keep it stable in the breeze. Outdoors, studio-oriented stands with lightweight aluminum bases and lightweight aluminum columns simply blow over in the breeze because they are too narrow in footprint,and simply are too light. I would encourage you to look at C-style stands from Matthews or Avenger because besides being good outdoors, they ALSO can support a 36x48 inch softbox and studio flash head in areas where there is not room,or time, to set up a boom stand with counterweight. The heavy STEEL lower bases and columns make these stands very bottom-heavy,and very safe,very stable, and long-lasting.